Dating in portland ore
Almost 95% of the mercury content of cinnabar ore can be recovered using this process.
Here is a typical sequence of operations used for the modern extraction and refining of mercury.
Higher purity mercury is needed for some limited applications and must be refined further. Commercial-grade mercury with 99.9% purity is called prime virgin-grade mercury.
Ultrapure mercury is usually produced by the triple-distillation method and is called triple-distilled mercury.
Mercury mining has ceased altogether in Spain, which until 1989 was the world's largest producer.
The process for extracting mercury from its ores has not changed much since Aristotle first described it over 2,300 years ago.
The use of mercury in paints, fungicides, and pesticides has been banned in the United States, and its use in the paper, felt, and glass-manufacturing processes has been voluntarily discontinued.
Worldwide, production of mercury is limited to only a few countries with relaxed environmental laws.
Other mercury ores include corderoite (Hg ), montroydite (Hg O), and calomel (Hg Cl). Mercury ores are formed underground when warm mineral solutions rise towards the earth's surface under the influence of volcanic action.
They are usually found in faulted and fractured rocks at relatively shallow depths of 3-3000 ft (1-1000 m).
Its principal applications are in the production of chlorine and caustic soda, and as a component of many electrical devices, including fluorescent and mercury-vapor lamps.